1. Field of the Invention
The present invention relates generally to lapping carriers, also known as row tools or row bending tools, for lapping rows of magneto-resistive elements. In particular, the present invention relates to a new lapping carrier and method for lapping rows of magneto-resistive elements.
2. Description of the Related Art
Magneto-resistive (MR) elements, typically in the form of read/write heads are produced by techniques similar to those used in semiconductor chip fabrication. Typically, a ceramic wafer is used as a substrate, and a plurality of deposition, lithographic and etching steps are carried out to form a generally repetitive array of MR elements. As wafer processing is completed, typically the wafer is sliced, such that the array of elements is cut into a plurality of longitudinal strips, each containing a plurality of MR elements. The units which house these read/write heads, also known as sliders or flying heads, are then further processed prior to dicing into individual units.
As the density of magnetic storage media has increased by orders of magnitude over the years, the distance from which such heads are offset from the magnetic storage media during read/write operations has been further decreased. As such, it has become necessary to tightly control the surface roughness, contour, as well as the distance from which the MR elements are spaced apart from the storage media. Accordingly, it has become conventional practice to lap or machine the surfaces of the MR elements that become the air bearing surfaces or top surfaces of the sliders, so as to precisely control surface contour, flatness, roughness, and critical spacing parameters. Typically, the surfaces that are created by slicing the MR elements into rows (i.e., the newly formed surfaces that extend perpendicular to the top and bottom surfaces of the wafer), are those surfaces which are precisely controlled by lapping.
U.S. Pat. No. 6,093,083, details a state of the art process and associated tools used in connection with lapping rows of MR elements. As is understood in the art, typically a row is bonded to a row carrier, which in turn is affixed to a row tool. The row carrier is typically a metal or ceramic plate to which the row is bonded. The row/row carrier assembly is then bonded to the row tool. The row tool is configured so as to have a plurality of individually adjustable movable elements (e.g., such as in the form of fingers) that adjust the relative height or depth of individual portions of the row, so as to optimize the degree of lapping during the lapping process to achieve a desired resistance in MR row (strip) and flatness.
U.S. Pat. No. 6,274,524 discloses electrostatic discharge dissipative components used in various applications, including magneto-resistive head manufacture. However, such components have been found to lack performance in practical use.
While state of the art processes and associated tools are believed to be effective, a need continues to exist in the art for improved techniques and tools for carrying out lapping of rows of MR elements.
According to an embodiment of the present invention, a lapping carrier is provided for machining a row of magneto-resistive (MR) elements. The lapping carrier includes a plurality of movable elements that terminate at an outer surface to form a generally planar mounting surface for the row of MR elements. The lapping carrier is generally formed of a ceramic material having electrostatic discharge (ESD) dissipative properties and high density.
Further, according to another embodiment of the present invention, a method for lapping a row of magneto-resistive (MR) elements is provided, in which a row of MR elements is mounted to the lapping carrier described above, and the row is then machined to remove material therefrom.
Another embodiment of the invention calls for a lapping carrier assembly, including a lapping carrier for machining a row of magneto-resistive elements, the lapping carrier including a plurality of movable elements, the movable elements terminating at an outer surface to form a generally planar mounting surface for a row of magneto-resistive elements. The lapping carrier is generally formed of a ceramic material having electrostatic discharge (ESD) dissipative properties and high density. The lapping carrier assembly further includes an actuator assembly including a plurality of transducers adapted to bias individual movable elements